On cherche à étudier l’effet de trois facteurs sur le transcriptome des racines d’Arabidopsis thaliana. Le CO2, au cours des études préliminaires, s’est montré peu influent en conditions contrôles de fer et de nitrates, et accentué en cas de stress nutritionnel. Nous reprennons ces résultats avec des fonctions génériques et propres pour en faire le résumé et de jolis graphes.

## Warning in scan(file = file, what = what, sep = sep, quote = quote, dec = dec, :
## EOF within quoted string
## Warning in scan(file = file, what = what, sep = sep, quote = quote, dec = dec, :
## number of items read is not a multiple of the number of columns

Import des données : matrice d’expression

On a, pour chaque gène et chaque condition, son niveau d’expression en sortie de quantification. On labelle les conditions avec le code suivant : lettre majuscule pour le niveau fort, minuscule pour le niveau faible. Le réplicat est donné après l’underscore.

[1] "cnF_3"
[1] At_AmbientCO2_LowNitrate_Fe1
48 Levels: At_AmbientCO2_HighNitrate_Fe1 ... Sl_ElevatedCO2_LowNitrate_FeStarvation3
[1] "At_AmbientCO2_LowNitrate_Fe"
          cNF_3 cNF_2 cNF_1 cnF_2 cnF_1 cnF_3 CNF_1 CnF_2 CnF_1 CnF_3 cNf_1
AT1G01010  1526  1006  1116  1275   967  1018   854  1132  1294  1364  2325
AT1G01020   416   285   289   349   364   370   226   513   502   561   461
AT1G01030    31    15    19    29    36    28    12    47    34    47    18
          cnf_2 cnf_1 cNf_2 cNf_3 cnf_3 Cnf_3 CNf_1 Cnf_1 Cnf_2 CNf_3 CNf_2
AT1G01010  2113  2193  2564  2364  2074  1987  2027  1754  1697  1537  1898
AT1G01020   407   432   614   380   502   484   467   426   415   413   462
AT1G01030    40    32    44    37    27    42    39    36    40    37    37
          CNF_3 CNF_2
AT1G01010   816   912
AT1G01020   223   312
AT1G01030    15    19
 [ reached 'max' / getOption("max.print") -- omitted 3 rows ]
[1] 23342    24

Effet fer en conditions contrôle

On définit les conditions contrôle comme suit : CO2 ambiant et fort fer.

  (Intercept) groupcNf
1           1        0
2           1        0
3           1        0
4           1        1
5           1        1
6           1        1
attr(,"assign")
[1] 0 1
attr(,"contrasts")
attr(,"contrasts")$group
[1] "contr.treatment"

[1] "cNF_3" "cNF_2" "cNF_1" "cNf_1" "cNf_2" "cNf_3"
    cNF_3     cNF_2     cNF_1     cNf_1     cNf_2     cNf_3 
0.9844303 0.9894266 0.9466501 1.0201203 1.0475235 1.0118491 

[1] "7341  genes DE"

Fort CO2

  (Intercept) groupCNf
1           1        0
2           1        0
3           1        0
4           1        1
5           1        1
6           1        1
attr(,"assign")
[1] 0 1
attr(,"contrasts")
attr(,"contrasts")$group
[1] "contr.treatment"

[1] "CNF_1" "CNF_3" "CNF_2" "CNf_1" "CNf_3" "CNf_2"
    CNF_1     CNF_3     CNF_2     CNf_1     CNf_3     CNf_2 
0.9778008 0.9263592 0.9875116 1.0165429 1.0509593 1.0408262 

[1] "7531  genes DE"

Low nitrate

  (Intercept) groupcnf
1           1        0
2           1        0
3           1        0
4           1        1
5           1        1
6           1        1
attr(,"assign")
[1] 0 1
attr(,"contrasts")
attr(,"contrasts")$group
[1] "contr.treatment"

[1] "cnF_2" "cnF_1" "cnF_3" "cnf_2" "cnf_1" "cnf_3"
    cnF_2     cnF_1     cnF_3     cnf_2     cnf_1     cnf_3 
0.9904890 1.0044366 0.9970741 0.9941176 1.0125589 1.0013239 

[1] "10410  genes DE"

Low nitrate and high CO2

  (Intercept) groupCnf
1           1        0
2           1        0
3           1        0
4           1        1
5           1        1
6           1        1
attr(,"assign")
[1] 0 1
attr(,"contrasts")
attr(,"contrasts")$group
[1] "contr.treatment"

[1] "CnF_2" "CnF_1" "CnF_3" "Cnf_3" "Cnf_1" "Cnf_2"
    CnF_2     CnF_1     CnF_3     Cnf_3     Cnf_1     Cnf_2 
1.0422944 1.0193300 1.0235403 0.9418015 0.9881213 0.9849125 

[1] "9520  genes DE"

Venn diagram

On visualise les gènes différentiellement exprimés en commun entre les différents niveaux des autres facteurs.

    gene_id   a.value   m.value       p.value       q.value rank estimatedDEG
1 AT1G13609  7.022011 11.082911  0.000000e+00  0.000000e+00    1            1
2 AT5G46900  7.660301 -7.607017 1.409723e-238 1.645287e-234    2            1
3 AT4G16370 11.521065  4.656174 2.715051e-238 2.112491e-234    3            1
4 AT1G52120  7.149774  6.073429 9.140222e-228 5.333777e-224    4            1
5 AT2G14247  7.965909  7.154585 8.076178e-223 3.770283e-219    5            1
6 AT1G17180  9.627023  5.335590 3.027245e-222 1.177699e-218    6            1
7 AT1G56430  9.400294  4.597719 6.213489e-216 2.071932e-212    7            1
8 AT5G46890  8.210122 -6.222259 1.706847e-210 4.980152e-207    8            1
9 AT3G03660  9.155803  4.515112 1.410258e-208 3.657583e-205    9            1
  upreg
1     1
2     0
3     1
4     1
5     1
6     1
7     1
8     0
9     1
 [ reached 'max' / getOption("max.print") -- omitted 7332 rows ]
    gene_id   a.value    m.value       p.value       q.value rank estimatedDEG
1 AT5G46900 -2.678878 -13.407381  0.000000e+00  0.000000e+00    1            1
2 AT5G46890  6.968087  -8.694677 1.492985e-312 1.742463e-308    2            1
3 AT5G44130  7.112045  -7.240253 6.527318e-281 5.078689e-277    3            1
4 AT1G13609  5.865935  12.253662 4.622108e-280 2.697231e-276    4            1
5 AT4G12520  7.455945  -7.046251 9.796516e-252 4.573406e-248    5            1
6 AT2G14247  7.842448   6.150042 1.889832e-246 7.352077e-243    6            1
7 AT4G33790  7.405395  -5.522115 1.501468e-219 5.006754e-216    7            1
8 AT4G15290  8.210109  -4.836956 6.657053e-219 1.942362e-215    8            1
9 AT1G56430  9.131468   5.086270 4.343399e-214 1.126485e-210    9            1
  upreg
1     0
2     0
3     0
4     1
5     0
6     1
7     0
8     0
9     1
 [ reached 'max' / getOption("max.print") -- omitted 7522 rows ]
    gene_id  a.value   m.value p.value q.value rank estimatedDEG upreg
1 AT1G19900 8.649998 -5.822602       0       0   13            1     0
2 AT1G53830 8.899211 -4.863803       0       0   13            1     0
3 AT1G54970 8.404367 -5.667750       0       0   13            1     0
4 AT1G69880 7.979638  5.814494       0       0   13            1     1
5 AT2G30670 9.987564  6.434368       0       0   13            1     1
6 AT2G39040 7.134149 -7.226335       0       0   13            1     0
7 AT3G08860 9.230476  6.747882       0       0   13            1     1
8 AT3G44300 9.256365  6.105301       0       0   13            1     1
9 AT3G62680 9.700786 -5.044145       0       0   13            1     0
 [ reached 'max' / getOption("max.print") -- omitted 10401 rows ]
    gene_id   a.value   m.value       p.value       q.value rank estimatedDEG
1 AT1G13609  4.937553 12.969206  0.000000e+00  0.000000e+00  4.5            1
2 AT2G29460  8.151641  5.503782  0.000000e+00  0.000000e+00  4.5            1
3 AT2G43510  5.518930 10.224305  0.000000e+00  0.000000e+00  4.5            1
4 AT3G44300  9.877015  5.799534  0.000000e+00  0.000000e+00  4.5            1
5 AT4G31970  7.704916 11.159530  0.000000e+00  0.000000e+00  4.5            1
6 AT4G33710 10.709176  7.716482  0.000000e+00  0.000000e+00  4.5            1
7 AT5G46890  6.542092 -9.060491  0.000000e+00  0.000000e+00  4.5            1
8 AT5G46900  6.312931 -9.442531  0.000000e+00  0.000000e+00  4.5            1
9 AT5G20230  8.858676  5.952530 4.298371e-322 1.114805e-318  9.0            1
  upreg
1     1
2     1
3     1
4     1
5     1
6     1
7     0
8     0
9     1
 [ reached 'max' / getOption("max.print") -- omitted 9511 rows ]

 

A work by Océane Cassan

oceane.cassan@supagro.fr